The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 04, 2011
Filed:
Mar. 07, 2008
Cheng Feng Lin, Taipei, TW;
Cheng Feng Lin, Taipei, TW;
Unipoint Electric Mfg, Co., Ltd., Taipei, TW;
Abstract
The present invention discloses a piston device which is disposed in a cylinder. The cylinder has a chamber including a bore and an inner wall. The piston device comprises a piston body and at least an annular ring. The piston body has a top side and a bottom side, the diameter of the piston body is smaller than the bore, and either one of the top side or the bottom side has a convex portion. The annular ring is clamped to the top side or the bottom side by engaging said convex portion, and the annular ring has a diameter slightly larger than the diameter of the piston body. While said piston therein moves reciprocally at which the axial direction of the cylinder, the annular ring slides against the inner wall but the piston body has no contact with said inner wall.